Agglomerated particulate lignosulfonate

ABSTRACT

An agglomerated particulate lignosulfonate material may be made by introducing or forming lignosulfonate microparticles in a fluidized bed agglomerator, and introducing sufficient heated gas and lignosulfonate liquid in the agglomerator to convert the microparticles to lignosulfonate granules of enlarged size. The granules may have an average size of at least 0.1 mm, and may be used to make a dry-blended cement additive or oil well cement that may be dustless, easily poured and stored, and rapidly dissolved in water.

FIELD

This invention relates to lignosulfonates.

BACKGROUND

Lignosulfonates are produced in large quantities as a byproduct of thepulp and paper industry, and have a number of valuable industrial uses.Lignosulfonates normally are used in their as-produced liquid form.Spray drying has been employed to convert the liquid to a finely-dividedpowder, and some end-users employ the resulting powder rather than theliquid. Lignosulfonate powder has also been mixed with lignosulfonateliquid to form a paste, then ground and sieved.

SUMMARY OF THE INVENTION

Liquid lignosulfonates include a substantial amount of water. The watercontent increases the product weight, volume and shipping cost and maybe an undesirable component or diluent for some end uses. Spray-driedlignosulfonates typically include an appreciable portion of very smalldusty particles. Grinding a dried lignosulfonate paste can consumeappreciable time and energy, and can yield a product having a broadrange of particle sizes including an appreciable portion of very smalldusty particles.

The present invention provides in one aspect a method for making aparticulate material, which method comprises:

-   -   a) introducing or forming lignosulfonate microparticles in a        fluidized bed agglomerator;    -   b) introducing heated gas and lignosulfonate liquid in the        agglomerator; and    -   c) enlarging the microparticles to form lignosulfonate granules.

The invention provides in another aspect a particulate materialcomprising non-comminuted lignosulfonate granules having an average sizeof at least 0.1 mm.

The invention provides in a further aspect a method for making a cementadditive comprising dry-blending cement powder with non-comminutedlignosulfonate granules having an average size of at least 0.1 mm.

The invention provides in yet another aspect a cement additivecomprising a mixture of cement powder and non-comminuted lignosulfonategranules having an average size of at least 0.1 mm.

The invention provides in yet another aspect a concrete mixture or oilwell cement comprising a blend of cement, water, non-comminutedlignosulfonate granules having an average size of at least 0.1 mm andoptional aggregate or proppant.

The disclosed lignosulfonate granules may provide one or more advantagessuch as low manufacturing cost, dustless or near-dustless dispensingcharacteristics, desirable handling and storage characteristics, lowhydroscopicity and rapid aqueous dissolution.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic view of one embodiment of the disclosedmanufacturing method;

FIG. 2 is a schematic view of another embodiment of the disclosedmanufacturing method;

FIG. 3 is a graph showing particle size distribution data for aspray-dried lignosulfonate powder and nine non-comminuted lignosulfonategranule samples;

FIG. 4 is a graph showing particle size distribution data for anaphthalenesulphonic acid condensation product cement additive and forthree non-comminuted calcium lignosulfonate granule samples;

FIG. 5 is a graph comparing concrete workability as a function of timefor the FIG. 4 calcium lignosulfonate granule samples and for aspray-dried lignosulfonate powder made from the same calciumlignosulfonate; and

FIG. 6 is a graph showing particle size distribution data for threenon-comminuted calcium lignosulfonate granule samples.

DETAILED DESCRIPTION

Unless the context indicates otherwise the following terms shall havethe following meaning and shall be applicable to the singular andplural:

The terms “a,” “an,” “the,” “at least one,” and “one or more” are usedinterchangeably. Thus a cement additive that contains “a” lignosulfonatematerial may include “one or more” lignosulfonate materials.

The term “average size” when used in respect to a collection ofparticles means the smallest sieve opening (expressed in mm) that willretain 50 wt. % of the particles in the collection using the measurementprocedure described in Example 1.

The term “comminuted” when used in respect to a particulate materialmeans that the particles have been fractured and reduced in size whiledry by cutting, grinding, pulverizing, triturating or other particlefracturing process employing externally-applied forces significantlygreater than the modest particle fracturing forces which may beexperienced by particles travelling though a fluidized bed agglomerator.

The term “dry” when used in respect to a particulate material means thatthe particles do not include visible moisture and are free-flowing whenpoured.

The term “granules” means a collection of particles whose average sizeis at least 0.1 mm.

The term phrase “lignosulfonate” includes sulfonated lignin, sulfitelignin reaction products, and spent sulfite liquors that may be furtherreacted, purified, fractionated or the like to producelignosulfonate-containing materials of interest.

The term “microparticles” means a collection of particles whose averagesize is less than 0.1 mm.

The term “Portland cement” includes pure Portland cement as well asblended cements containing Portland cement and a cement extender (e.g.,blast furnace slag, or fly ash and other pozzolans).

The terms “preferred” and “preferably” refer to embodiments of theinvention that may afford certain benefits, under certain circumstances.However, other embodiments may also be preferred, under the same orother circumstances. Furthermore, the recitation of one or morepreferred embodiments does not imply that other embodiments are notuseful, and is not intended to exclude other embodiments from the scopeof the invention.

The term “size” when used in respect to a particle means the smallestsieve opening (expressed in mm) that will enable the particle to passthrough the sieve using the measurement procedure described in Example1.

The recitation of a numerical range using endpoints includes all numberssubsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3,3.80, 4, 5, etc.). The recitation of sets of upper and lower endpoints(e.g., at least 1, at least 2, at least 3, and less than 10, less than 5and less than 4) includes all ranges that may be formed from suchendpoints (e.g., 1 to 10, 1 to 5, 2 to 10, 2 to 5, etc.).

FIG. 1 shows an exemplary schematic view of one embodiment of thedisclosed manufacturing method. Continuous fluid bed agglomerator 100includes a housing 102 containing fluidized bed 104. Lignosulfonatemicroparticles 106 may be introduced into fluidized bed 104 throughinlet chute 108 (e.g., as a spray-dried lignosulfonate powder), may beformed in fluidized bed 104 by adding lignosulfonate liquid 110 tofluidized bed 104, e.g., through spray nozzle 112 or other suitableinjector, or may be both introduced and formed in fluidized bed 104.Heated gas streams such as streams 114, 116, 118 and 120 (e.g., ofheated air) may be introduced into fluidized bed 104 through supplychambers 122, 124, 126 and 128 and distribution plate 130. Additionallignosulfonate liquid 110 may be introduced into fluidized bed 104 viaspray nozzles or other suitable injectors such as spray nozzles 132 and134. Exposure to the heated gas and liquid lignosulfonate in theagglomerator will cause the lignosulfonate microparticles toagglomerate, grow or otherwise enlarge in size. Spent process gas suchas gas streams 136, 138 may be removed from expansion zone 140 asfiltered gas stream 142 by passage through filters such as filters 144,146, 148, 150, 152, 154, 156 and 158 mounted in filter support plate160. Lignosulfonate granules 162 may be removed from fluidized bed 104through outlet chute 164. Microparticles and undersized agglomerates maybe separated from the granules 162 (using for example, airclassification) and returned to inlet chute 108 for furtheragglomeration or growth in fluidized bed 104, and the remaininglignosulfonate granules may be collected and used in various productapplications.

FIG. 2 shows an exemplary schematic view of another embodiment of thedisclosed manufacturing method. Batch fluid bed agglomerator 200includes a housing 202 containing fluidized bed 204. Lignosulfonatemicroparticles 206 may be introduced into fluidized bed 204 throughinlet pipes 208, 210. Heated gas streams such as streams 212, 214, 216and 218 (e.g., of heated air) may be introduced into fluidized bed 204through supply pipes 220, 222 and distribution plate 224. Additionallignosulfonate liquid 226 may be introduced into fluidized bed 204 viaspray nozzles or other suitable injectors such as spray nozzle 228.Exposure to the heated gas and liquid lignosulfonate in the agglomeratorwill cause the lignosulfonate microparticles to agglomerate, grow orotherwise enlarge in size. Spent process gas such as gas streams 230,232 may be removed from expansion zone 234. Lignosulfonate granules 236may be removed from fluidized bed 204 through outlet pipe 238.Microparticles and undersized agglomerates may be separated from thegranules 236 (using for example, air classification) and employed in orin place of the stream of lignosulfonate microparticles 206 when thenext lignosulfonate agglomerate batch is prepared in apparatus 200. Theremaining lignosulfonate granules may be collected and used in variousproduct applications.

A variety of apparatus configurations and process parameters may beemployed in an apparatus like that shown in FIG. 1 or FIG. 2. Forexample, a top spray lignosulfonate application may be employed in theFIG. 1 apparatus or a bottom spray lignosulfonate application may beemployed in the FIG. 2 apparatus. A stream of lignosulfonatemicroparticles may be introduced at the start of operating a continuousagglomeration apparatus like that shown in FIG. 1 and then switched off,with the apparatus thereafter being operated using only lignosulfonateliquid introduction. Process parameters including the introduction ratesfor lignosulfonate microparticles, lignosulfonate liquid and heated gas;the overall or localized gas stream and bed temperatures; and otherparameters which will be appreciated by persons having ordinary skill inthe art of fluidized bed agglomeration may be adjusted or otherwisealtered to control the rate and extent of microparticle agglomeration,growth or other enlargement. For example, the heated gas streamtemperatures for continuous fluidized bed agglomerator operation may beabout 170 to about 250° C. or about 170 to about 210° C., and the bedtemperatures for continuous fluidized bed agglomerator operation may beabout 60 to about 80° C. Bed retention times may for example be lessthan two hours, less than one hour, or about 15 to about 45 minutes.Desirably the bed temperatures, bed retention times and other conditionsare such that the lignosulfonate granules undergo the desired degree ofenlargement without becoming significantly oxidized or otherwise undulydegraded. The proportion of lignosulfonate microparticles used to makethe desired lignosulfonate granules having an average size of at least0.1 mm may for example represent 0 to about 40 or about 1 to about 35wt. % of the collected granules. The proportion of lignosulfonate liquidused to make such granules may for example represent 100 to about 60 orabout 99 to about 65 wt. % of the collected granules.

A variety of lignosulfonates may be employed to make the disclosedgranules. Exemplary lignosulfonates may be obtained from a variety ofsources including hardwoods, softwoods and recycling or effluentstreams. The lignosulfonates may be utilized in crude or pure forms,e.g., in an “as is” or whole liquor condition, or in a purifiedlignosulfonate form from which or in which sugars and other saccharideconstituents have been removed or destroyed, or from which or in whichinorganic constituents have been partially or fully eliminated. Thelignosulfonates may be utilized in salt forms including calciumlignosulfonates, sodium lignosulfonates, ammonium lignosulfonates,potassium lignosulfonates, magnesium lignosulfonates and mixtures orblends thereof. Lignosulfonates are available from a number of suppliersincluding Borregaard LignoTech, Georgia-Pacific Corporation, Lenzing AGand Tembec Inc.

A variety of fluid bed agglomerators may be employed to make thedisclosed granules. Exemplary agglomerators include those shown ordescribed in U.S. Pat. Nos. 3,913,847 (Glatt et al.) and 6,740,832 B1(Jacob et al.). Other fluidized bed agglomerators are available fromcommercial suppliers including Glatt Air Techniques, Inc. and Niro, Inc.The disclosed granules may also be prepared by modifying a fluidized beddryer to spray or otherwise add liquid lignosulfonate to heatedlignosulfonate particles. For example, a lignosulfonate liquid spraycould be added to the fluidized bed lignosulfonate powder reactordescribed in U.S. Pat. No. 3,746,740 (Markham et al.) and the operatingtemperatures and residence times described therein could be reduced tolimit or prevent lignosulfonate oxidation. The operating temperatures,residence times and spray liquid addition rates could then be adjustedto bring about lignosulfonate microparticle enlargement and theformation of lignosulfonate granules.

The collected granules may consist of or consist essentially oflignosulfonate and may be coated or uncoated. The granules may forexample have an average size of about 0.1 to about 10 mm, about 0.1 toabout 5 mm, about 0.1 to about 2 mm, about 0.1 to about 1 mm, or about0.1 to about 0.5 mm. The collected granules desirably contain little orno (e.g., less than 5 wt. %, less than 3 wt. % or less than 1 wt. %)particles having a size less than 0.1 mm. The granules also desirablyhave a higher density (for example, an uncompressed bulk density ofabout 550 to about 800 or about 560 to about 775 kg/m³) than spray-driedpowder made using the same lignosulfonate starting liquid. Whenmoistened or otherwise exposed to water or humid conditions, thegranules desirably exhibit slower moisture absorption, remainfree-flowing at higher moisture contents or are less prone to lumpformation than spray-dried powders made using the same lignosulfonatestarting liquid. When compared to such spray-dried powders, the granulesdesirably also have reduced tendency to leak from packaging (e.g., papersacks), emit little dust or substantially no dust when poured, have areduced tendency to remain behind in packaging when poured, or areeasily removed from a spill site if accidentally spilled.

The disclosed lignosulfonate granules may be used in a variety ofproducts and uses including cement additives, well cements (e.g., forgas, oil or water wells), pigment dispersants, battery separators,animal feeds and agricultural chemicals including the products or usesreferred to in U.S. Pat. Nos. 2,582,459 (Salathiel), 4,284,433(Aignesberger et al.), 5,215,584 (Buxbaum et al.), 5,728,209 (Bury etal.), 5,766,323 (Butler et al.), 6,238,847 B1 (Gargulak et al.),6,648,926 B2 (Berke et al.) and 6,840,318 B2 (Lee et al.) and inPublished PCT Application No. WO/01 36344 A2 (LignoTech USA, Inc.).

The disclosed granules have particular value in cement additives andwell cements, and can be provided in a dry particulate form which may bemuch more conveniently shipped, stored or dispensed than correspondingadditives made using lignosulfonate liquids or microparticle powders(e.g., spray-dried powders). The granules desirably provide comparableor improved fluidity, water content, set time retardation or airentrainment compared to cement additives made from spray-driedlignosulfonate powders made from the same lignosulfonate startingliquid. Cement additives and well cements containing the granules mayinclude a variety of adjuvants, for example other cement plasticizersand superplasticizers such as melamine sulfonates (MSF), naphthalenesulfonates (PNS), polycarboxylates and polycarboxylic ether (PCE)polymers. The total cement plasticizer or superplasticizer amount,including any lignosulfonate which may be present, may for example be upto about 100% of the cement weight employed in the final concrete orwell cement mixture, but desirably provide desired property improvementsat much lower addition levels, e.g., at about 0.1 to about 1% solidsbased on the cement weight. De-foaming agents, for exampletri-n-butylphosphate (TBP) and tri-iso-butylphosphate (TiBP) may beemployed, e.g., in amounts of about 0.1-0.2 wt. % based on the cementweight. A variety of biocides or other preservatives may be employed,including compounds which give off formaldehyde (at, e.g., about 0.1-0.2wt. % based on the cement weight), phenolic compounds (at, e.g., about0.2-0.5 wt. % based on the cement weight) and isothiazolinonepreparations (at, e.g., about 0.02-0.2 wt. % based on the cementweight). Desirably however the disclosed granules may be packagedwithout requiring biocides. Retarders, for example sucrose, gluconates,phosphates (e.g., tetrapotassium pyrophosphate, sodium tripolyphosphateand sodium hexametaphosphate) may be employed, e.g., in amounts of about0.2-2 wt. % based on the cement weight. Accelerators, for examplesilicates and salts thereof including the sodium or potassium salts,aluminates, carbonates, formiates, amorphous aluminum hydroxides andaluminum sulfate may be employed, e.g., in amounts of about 1-3 wt. %based on the cement weight. Air-entraining agents, for example naturalresins (e.g., resin soap, tall resins, colophony and other gum resins,and root resins) and synthetic non-ionic or ionic surfactants (e.g.,alkylpolyglycol ethers, alkylsulfates and alkylsulfonates) may beemployed, e.g., in amounts of about 0.5-1 wt. % based on the cementweight. Stabilizers and sedimentation reducers may also be employed, forexample starch derivatives and other polysaccharides (e.g., celluloseether, starch ether, xanthan gum and whelan gum), synthetic highmolecular weight polymers (e.g., polyethylene oxides and polyacrylates)and fine grained inorganic substances with large specific surfaces(e.g., silica powder, silica suspensions and silica sols), e.g., inamounts up to about 1 wt. % based on the cement weight. The dry natureof the disclosed granules permits them to be used to make dry cementadditives which may be combined with cement, aggregate and water toprepare concrete mixtures at reduced dilution compared to concretemixtures made using liquid lignosulfonate additives. The disclosedgranules also may be combined with cement, proppants and water to makeoil well cements with desirable fluidity and curing characteristics.

The invention is further described in the following Examples, in whichall parts and percentages are by weight unless otherwise indicated.

Example 1 Agglomerated Granules

A continuous feed GLATT™ fluidized bed agglomerator equipped withsprayheads for bottom spray liquid introduction was employed to make aseries of lignosulfonate granules. The agglomerator was initiallyoperated using spray-dried lignosulfonate microparticles (made usingBORRESPERSE™ CA-SA lignosulfonate liquid from Borregaard LignoTech) as aseed feed, additional BORRESPERSE CA-SA lignosulfonate liquid in thebottom spray units as an agglomerating liquid feed, and process airheated to about 190° C. The seed and liquid feed streams were initiallyintroduced in a 30:70 weight ratio. The agglomerator was operated atfull capacity using a bed residence time of about 15-20 minutes, and at50% capacity using a bed residence time of about 25-30 minutes. Themicroparticle feed could be switched off shortly after the start of eachrun and similar granules could be obtained by increasing the bedresidence time to about 25-30 minutes for operation at full capacity andabout 40-45 minutes for operation at 50% capacity. A series of 9 granulesamples was prepared. Particle size distribution curves for thesesamples are identified in FIG. 3 as Curve B through Curve J, along witha comparison particle size distribution curve (Curve A) for thespray-dried lignosulfonate powder. FIG. 3 employs a logarithmichorizontal particle size axis, and the differences in sample particlesizes thus appear at first glance to be somewhat compressed. Due to thesignificantly smaller average particle size of the Curve A spray-driedcomparison sample, laser diffraction was employed to measure itsparticle size distribution. Sieves were used to measure particle sizedistributions for the Curve B through Curve J granule samples. The sievemeasurement procedure employed approximately 200 g portions of thetested granules. The granules were poured over a stack of measurementsieves in graduated sizes and shaken for 5 minutes using a Model1132-2-A sieve vibrator (from Pascall Engineering), followed by weighingto determine the granule weight in each sieve.

The results in FIG. 3 show that the Curve A spray-dried powder had anaverage particle size of about 0.09 mm and a relatively broad particlesize distribution whereas the granules produced using the fluidized bedagglomerator had average particle sizes of about 0.11 to about 0.6 mmand much narrower particle size distributions. For the Curve Aspray-dried powder, more than half the powder by weight had a particlesize less than 0.1 mm. For the granule sample identified as Curve B,less than about 35 wt. % of the granules had a particle size less than0.1 mm. For the Curve C through Curve J granule samples, less than about3 wt. % of the granules had a particle size less than 0.1 mm.

Dry flow properties were evaluated by individually placing 200 g samplesof each granule and of the Curve A powder in a 360 mm tall by 70 mmdiameter vertical plastic cylinder whose lower end had been fitted witha plastic funnel. The funnel had a 22 mm diameter outlet placed 150 mmabove a Model PG5002-S laboratory balance (from Mettler-Toledo). Flowcurves were prepared by measuring the total sample weight under thefunnel at one second intervals. Depending on the granule sample averageparticle size, the granules exited the funnel within 9-12 seconds afterthe start of measurement, with larger average particle size samplesexiting more quickly than smaller average particle size samples. TheCurve A powder sample remained in the cylinder and funnel and did notdrop onto the balance.

Aqueous dissolving speed was evaluated by individually placingsufficient amounts of each granule sample in deionized water to provide45% or 50% dry matter in a 2 Kg solution. The water was stirred in a 2 Lbeaker at approximately 550 rpm using a model RW 20 stirring motor (fromKanke & Kunkel) equipped with a two-bladed metal propeller.

The sample was dropped onto the water all at once and a stopwatch wasemployed to measure the time required to obtain a uniformly dissolvedmixture. The 45% dry matter solutions dissolved in 10 to 30 minutes, andthe 50% dry matter solutions dissolved in 30 to 45 minutes. In acomparison run, a 45% dry matter solution made using the Curve Aspray-dried powder required 60 minutes to dissolve, and a 50% dry mattersolution required 75 minutes to dissolve.

Example 2 Cement Additives

Using the method of Example 1, lignosulfonate granules were preparedusing BORRESPERSE™ CA calcium lignosulfonate from Borregaard LignoTech.FIG. 4 shows a particle size distribution curve (Curve K) for acomparison cement additive sold as TAMOL™ NH 7519 naphthalenesulphonicacid condensation product (from BASF) and three particle sizedistribution curves for fine (Curve L), medium (Curve M) and coarse(Curve N) granules made using BORRESPERSE CA calcium lignosulfonate. Thehorizontal axis in FIG. 4 shows the sieve opening in mm and isnon-linear.

Concrete mixtures were prepared in 60 L batches using EN 197-1 CEM 142.5R Portland cement (Standard Portland 30 from Embra, 350 kg/m³ density),graded aggregate sized in accordance with DIN EN 480-1 (0-8 mm 55 wt. %;8-12 mm 22.5 wt. %; 12-16 mm 22.5 wt. %; 16 mm D_(max)) and a 0.5water:cement weight ratio, together with the FIG. 4 samples as cementadditives at 0.28 to 0.3% solids by weight of cement (sbwc). A concretemixture was also prepared using lignosulfonate powder made fromspray-dried BORRESPERSE CA calcium lignosulfonate. The concrete mixtureswere evaluated for air content, density, set time, initial slump andslump loss. The dry individual cement additives were also placed in a 1L calibrated container and evaluated to determine their uncompacted bulkdensities. The uncompacted samples were then vibrated for 30 secondsusing a vibration table. The calibrated container was refilled and againvibrated for another 30 seconds and a density for the resultingcompacted additive was recorded. The individual cement additives werealso evaluated to determine wt. % dry matter. The results of theconcrete mixture and additive evaluations are shown below in Table A.Slump loss results are also shown in FIG. 5 for the spray-driedlignosulfonate powder (Curve O) and the fine (Curve P), medium (Curve Q)and coarse (Curve R) lignosulfonate granules also shown in FIG. 4. Theresults in FIG. 5 and Table A show that compared to the spray-driedlignosulfonate, the granulated lignosulfonates had increased aircontent, similar initial slump, improved slump retention and similar settime. Compared to the naphthalenesulphonic acid condensation productpowder, the granulated lignosulfonates had increased air content,greater initial slump and longer set time. Both the spray-driedlignosulfonate and the naphthalenesulphonic acid condensation productpowder formed considerable dust when poured, whereas no dusting wasobserved when pouring the granulated lignosulfonates.

TABLE A Concrete and Additive Properties TAMOL Fine Medium Coarse PowderSpray-dried BORRESPERSE BORRESPERSE BORRESPERSE (Curve BORRESPERSE CAGranules CA Granules CA Granules K) CA Powder (Curves L and P) (Curves Mand Q) (Curves N and R) Dosage (% sbwc) 0.30 0.30 0.29 0.30 0.28 AirContent (vol. %) 2.2 3.7 6.7 6.0 6.8 Density (kg/m³) 2393 2341 2282 22922271 Set Time (Hours) 4.0 10.5 9.8 9.8 10.1 Slump (mm) at Time:  0 Min73 200 205 202 208 15 Min 200 198 207 204 30 Min 182 180 187 195 60 Min135 150 165 178 90 Min Bulk Density (kg/m³): Uncompacted 435 536 565 563654 Vibrated 1 Min 520 649 657 659 765 Dry Matter (%) 88.1 92.8 93.992.3 92.2

Example 3 Additional Cement Additives

Using the method of Example 1, lignosulfonate granules were preparedusing BORRESPERSE™ NA sodium lignosulfonate from Borregaard LignoTech.FIG. 6 shows particle size distribution curves for the resulting fine(Curve S), medium (Curve T) and coarse (Curve U) granules. Thehorizontal axis in FIG. 6 shows the sieve opening in mm and isnon-linear. Using the method of Example 2, the granules and alignosulfonate powder made from spray-dried BORRESPERSE NA sodiumlignosulfonate were used as cement additives at 0.30% sbwc, andevaluated for air content, density, set time, initial slump and slumploss. The dry additives were also evaluated for uncompacted andcompacted bulk densities and wt. % dry matter. The results are shownbelow in Table B. Compared to the spray-dried lignosulfonate, thegranulated lignosulfonates had slightly increased air content, lowerinitial slump, similar slump retention and similar set time. Thespray-dried lignosulfonate powder formed considerable dust when poured,whereas no dusting was observed when pouring the granulatedlignosulfonates.

TABLE B Concrete and Additive Properties Fine Medium Coarse Spray-driedBORRESPERSE BORRESPERSE BORRESPERSE BORRESPERSE NA Granules NA GranulesNA Granules CA Powder (Curve S) (Curve T) (Curve U) Dosage (% sbwc) 0.300.30 0.30 0.30 Air Content (vol. %) 3.6 4.4 4.3 4.4 Density (kg/m³) 23492331 2329 2329 Set Time (Hours) 6.6 6.6 7.0 6.5 Slump (mm) at Time:  0Min 200 179 184 177 15 Min 178 157 143 153 30 Min 144 90 107 90 60 Min83 78 87 64 90 Min Bulk Density (kg/m³): Uncompacted 577 560 580 562Vibrated 1 Min 689 660 685 648 Dry Matter (%) 94.9 92.0 92.0 91.7

Having thus described the preferred embodiments of the presentinvention, those of skill in the art will readily appreciate that theteachings found herein may be applied to yet other embodiments withinthe scope of the claims hereto attached. The complete disclosures of allpatents, patent documents, and publications are incorporated herein byreference as if individually incorporated.

1. A method for making a particulate material, which method comprises:a) introducing or forming lignosulfonate microparticles in a fluidizedbed agglomerator; b) introducing heated gas and lignosulfonate liquid inthe agglomerator; and c) enlarging the microparticles to formlignosulfonate granules.
 2. A method according to claim 1 comprisingintroducing the lignosulfonate liquid by spraying it onto the fluidizedbed.
 3. A method according to claim 1 wherein the heated gas is air atabout 170 to about 250° C.
 4. A method according to claim 1 wherein thebed has a bed temperature of about 60 to about 80° C.
 5. A methodaccording to claim 1 comprising enlarging the microparticles to formlignosulfonate granules having an average size of about 0.1 to about 10mm.
 6. A method according to claim 1 comprising enlarging themicroparticles to form lignosulfonate granules having an average size ofabout 0.1 to about 2 mm.
 7. A method according to claim 1 comprisingforming lignosulfonate granules having an uncompressed bulk density ofabout 550 to about 800 kg/m³.
 8. Particulate material comprisingnon-comminuted lignosulfonate granules having an average size of atleast 0.1 mm.
 9. A particulate material according to claim 8 wherein thegranules have an average size of about 0.1 to about 10 mm.
 10. Aparticulate material according to claim 8 wherein the granules have anuncompressed bulk density of about 550 to about 800 kg/m³.
 11. Aparticulate material according to claim 8 wherein the granules arefree-flowing and emit substantially no dust when poured.
 12. Aparticulate material according to claim 8 wherein the granules consistessentially of calcium, sodium or magnesium lignosulfonate.
 13. A methodfor making a cement additive comprising dry-blending cement powder withnon-comminuted lignosulfonate granules having an average size of atleast 0.1 mm.
 14. A method according to claim 13 wherein the cementpowder comprises Portland cement.
 15. A method according to claim 13wherein the granules have an average size of about 0.1 to about 10 mm.16. A method according to claim 13 wherein the granules have anuncompressed bulk density of about 550 to about 800 kg/m³.
 17. A methodaccording to claim 13 wherein the granules consist essentially ofcalcium, sodium or magnesium lignosulfonate.
 18. A method according toclaim 13 comprising dry-blending the powder with about 0.1 to about 1wt. % granules based on the cement weight.
 19. A method according toclaim 13 further comprising dry-blending the powder with a melaminesulfonate, naphthalene sulfonate, polycarboxylate or polycarboxylicether.
 20. A cement additive comprising a mixture of cement powder andnon-comminuted lignosulfonate granules having an average size of atleast 0.1 mm.
 21. An additive according to claim 20 wherein the cementpowder comprises Portland cement.
 22. An additive according to claim 20wherein the granules have an average size of about 0.1 to about 10 mm.23. An additive according to claim 20 wherein the granules consistessentially of calcium, sodium or magnesium lignosulfonate.
 24. Anadditive according to claim 20 wherein the additive further comprisesmelamine sulfonate, naphthalene sulfonate, polycarboxylate orpolycarboxylic ether.
 25. A concrete mixture or oil well cementcomprising a blend of cement, water, non-comminuted lignosulfonategranules having an average size of at least 0.1 mm and optionalaggregate or proppant.